A datacenter is a facility used to house a collection of computer servers and associated components, typically network hardware. The collection of computer servers is often called a “server cluster” or “server farm,” and is designed to provide services far beyond the capability of a single machine. The networking hardware typically includes network switches and/or routers which enable communication between the different parts of the server farm and the users of the server farm.
Server farms are commonly used for cluster computing, web services, remote data storage, web hosting, and other web services. Server farms are increasingly being used by enterprises instead of, or in addition to, mainframe computers. As the demand for server farms continues to increase, a need exists to limit the cost of operating a datacenter. Often, a large part of the cost of operating a datacenter is related to the datacenter's cooling systems and the total electricity cost. To this end, enterprises typically try to maximize power usage effectiveness (PUE) of a datacenter, which is a measure of how efficiently a computer datacenter uses its power; specifically, how much of the power is actually used by the computing equipment in contrast to cooling and other overhead.